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Chronic wounds, including diabetic and venous ulcers, represent disruption of normal healing processes resulting in a pathological state of nonhealing cutaneous inflammation. They place an increasingly significant economic burden on healthcare providers as their prevalence is rising in keeping with an aging population. Current treatment modalities are slow acting and resource intensive. Bioengineered skin substitutes from autogenic, allogenic, or xenogenic sources have emerged as a new and alternative therapeutic option. A range of such products is licensed for clinical use, which differ in terms of structure and cellular content. Placed directly onto a prepared wound bed, skin substitutes may stimulate or accelerate healing by promoting revascularization, cellular migration, and repopulation of wound fields through provision of an appropriate scaffold material to facilitate these processes. Products containing fetal or autologous cells also benefit from early release of bioactive molecules including growth factors and cytokines. To date, limited numbers of randomized controlled trials studying skin substitutes have been published but evidence from case series and case-control studies is encouraging. This review discusses chronic wound biology, the influence that skin substitutes can exert on this environment, the products currently available, and examines the evidence for their use in chronic wound management.

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Laparoscopic surgery has become the gold standard for many operative procedures in the last 20 years. Its advantages over open surgery are well documented; however, the drive to reduce the trauma of surgical access persists. Laparoscopic techniques utilising only one umbilical port may represent the next step in this surgical evolution. They have been given a myriad of names (single-port access surgery (SPA), one-port umbilical surgery (OPUS), transumbilical endoscopic surgery (TUES) etc) since their inception, with no standardised acronym to date. 1 Single incision laparoscopic surgery (SILS) is an umbrella term used in this article to encompass all such single incision laparoscopic techniques, which allow potentially 'scarless' surgery as the wound is hidden within the umbilicus. Many groups have reported on the feasibility of the technique and its initial success but there have been very few significant trials. There is still no consensus and this field therefore represents a major focus for research and development. A MEDLINE ® search using multiple Medical Subject Headings (MeSH) terms pertaining to this topic highlighted 464 relevant articles in the literature. This article aims to present the current possibilities offered by this technique within general surgery and the evidence supporting it. DiscussionThere is still much debate over whether SILS is the future of laparoscopic surgery or just a passing fad. SILS was first described in general surgery in 1997 to perform laparoscopic cholecystectomies 1,2 and appendicectomies 1,3 but enthusiasm was limited because of poor equipment and technical support. In 2005 a resurgence was initiated in urology by Hirano et al. 4 Technical improvements that enabled this revival included bent or articulating instruments, adjustments in laparoscopes, several adjacently placed trocars through one incision and special multilumen ports that allow simultaneous multiple instrument insertion. 1 Many of the big healthcare manufacturers have seen this emerging market and new operative hardware is being developed to facilitate the technique. Devices like the TriPort (Advanced Surgical Concepts, Wicklow, Ireland) (Fig 1), the AirSeal ® (SurgiQuest Inc, Orange, CT, US) (Fig 3) and the SILS ™ port (Covidien, Norwalk, CT, US) have made single site surgery easier and more efficient. A return to SILS cholecystectomies followed and this is the most studied general surgery procedure using the technique. However, the repertoire of operations amenable to SILS is expanding and recently published papers describe SILS approaches for totally extraperitoneal inguinal hernia repair, 6 Single incision laparoscopic surgery (SILS) is a rapidly developing field that may represent the future of laparoscopic surgery. The major advantage of SILS over standard laparoscopic surgery is in cosmesis, with surgery becoming essentially scarless if the incision is hidden within the umbilicus. Only one incision is required so the risk of potential complications like port site hernias, haematomas and wound in...

Optical coherence tomography enabled accurate assessment of healing tissue comparable with histological analysis of biopsy specimens. This noninvasive tool is highly suited to wound assessment and may represent a diagnostic alternative to punch biopsies.

BackgroundThe influence of skin substitutes upon angiogenesis during wound healing is unclear.ObjectivesTo compare the angiogenic response in acute cutaneous human wounds treated with autogenic, allogenic and xenogenic skin substitutes to those left to heal by secondary intention.MethodsOn day 0, four 5mm full-thickness punch biopsies were harvested from fifty healthy volunteers (sites 1-4). In all cases, site 1 healed by secondary intention (control), site 2 was treated with collagen-GAG scaffold (CG), cadaveric decellularised dermis (DCD) was applied to site 3, whilst excised tissue was re-inserted into site 4 (autograft). Depending on study group allocation, healing tissue from sites 1-4 was excised on day 7, 14, 21 or 28. All specimens were bisected, with half used in histological and immunohistochemical evaluation whilst extracted RNA from the remainder enabled whole genome microarrays and qRT-PCR of highlighted angiogenesis-related genes. All wounds were serially imaged over 6 weeks using laser-doppler imaging and spectrophotometric intracutaneous analysis.ResultsInherent structural differences between skin substitutes influenced the distribution and organisation of capillary networks within regenerating dermis. Haemoglobin flux (p = 0.0035), oxyhaemoglobin concentration (p = 0.0005), and vessel number derived from CD31-based immunohistochemistry (p = 0.046) were significantly greater in DCD wounds at later time points. This correlated with time-matched increases in mRNA expression of membrane-type 6 matrix metalloproteinase (MT6-MMP) (p = 0.021) and prokineticin 2 (PROK2) (p = 0.004).ConclusionCorroborating evidence from invasive and non-invasive modalities demonstrated that treatment with DCD resulted in increased angiogenesis after wounding. Significantly elevated mRNA expression of pro-angiogenic PROK2 and extracellular matrix protease MT6-MMP seen only in the DCD group may contribute to observed responses.

Skin substitutes are heterogeneous biomaterials designed to accelerate wound healing through provision of replacement extracellular matrix. Despite growing evidence for their use in chronic wounds, the role of skin substitutes in acute wound management and their influence on fibrogenesis remains unclear. Skin substitute characteristics including biocompatibility, porosity, and elasticity strongly influence cellular behavior during wound healing. Thus, we hypothesize that structural and biomechanical variation between biomaterials may induce differential scar formation after cutaneous injury. The following human prospective cohort study was designed to investigate this premise. Four 5‐mm full thickness punch biopsies were harvested from 50 volunteers. In all cases, site 1 healed by secondary intention, site 2 was treated with collagen‐GAG scaffold (CG), and decellularised dermis (DCD) was applied to site 3 while tissue extracted from site 4 was replaced (autograft). Healing tissue was assessed weekly with optical coherence tomography (OCT), before being excised on days 7, 14, 21, or 28 depending on study group allocation for later histological and immunohistochemical evaluation. Extracted RNA was used in microarray analysis and polymerase chain reaction of highlighted genes. Autograft treatment resulted in minimal fibrosis confirmed immunohistochemically and with OCT through significantly lower collagen I levels (p = 0.047 and 0.03) and reduced mean grayscale values (p = 0.038 and 0.015), respectively. DCD developed intermediate scar formation with partial rete ridge reformation and reduced fasiculonodular fibrosis. It was uniquely associated with late up‐regulation of matrix metalloproteinases 1 and 3, oncostatin M, and interleukin‐10 (p = 0.007, 0.04, 0.019, 0.019). Regenerated dermis was significantly thicker in DCD and autografts 28 days post‐injury compared with control and CG samples (p = 0.003 and <0.0001). In conclusion, variable fibrotic outcomes were observed in skin substitute‐treated wounds with reduced scarring in autograft and DCD samples compared with controls. OCT enabled concurrent assessment of wound morphology and quantification of dermal fibrosis.

We report the case of a 16 year old male who was the victim of a drive by shooting sustaining the rare but recognised complication of cardiovascular bullet embolism. He was seen as a trauma call in the emergency department and CT scanning revealed 70 shotgun pellets scattered throughout left sided sub-cutaneous tissues of the head and neck, and more significantly a single pellet within the right atrium. It is believed to have got there via injury to the left brachiocephalic vein which was demonstrated by extravasation of contrast on the CT scan. He remained stable throughout admission and the injury was managed conservatively. Serial scanning showed the pellet had subsequently migrated into the right ventricle where it has remained since, presumably having become epithelialised. This case report highlights the importance of repeated scanning for the possibility of projectile migration within the cardiovascular system in similar cases of penetrating injury.